Answer:
Option C is the correct answer.
Step-by-step explanation:
Let x be the time in minutes it takes to fill the sink using only the hot water.
We have it takes 5 minutes to fill the sink using only the cold water.
Rate at which cold water is flowing is given by
[tex]r_{cold}=\frac{1}{5}sink/min[/tex]
It takes X minutes to fill the sink using only the cold water.
[tex]r_{hot}=\frac{1}{X}sink/min[/tex]
If both of them are use it takes 2 minutes.
[tex]\texttt{Part of sink filled by cold water = }2\times \frac{1}{5}=\frac{2}{5}\\\\\texttt{Part of sink filled by hot water = }2\times \frac{1}{X}=\frac{2}{X}[/tex]
Comparing the options given,
We can see option C is the correct answer.